1. Field of the Invention
Aspects of the present invention relate to an array substrate for an x-ray detector and an x-ray detector having the array substrate installed therein and, more particularly, aspects of the present invention relate to an array substrate for an x-ray detector that is capable of reducing a manufacturing cost thereof and of improving an image display quality thereof, a method of manufacturing the array substrate, an x-ray detector having the array substrate installed therein, and a method of manufacturing the x-ray detector.
2. Description of the Related Art
Recently, in order to process medical image information for medical appliances, a digital radiograph (DR) has been widely accepted. The DR may be classified into a charge-coupled device (CCD) DR, a complementary metal-oxide semiconductor (CMOS) DR, and/or a flat panel (FP) DR in accordance with a kind of sensor, which is installed therein, that converts green light emitted from a scintillator.
The CCD DR and CMOS DR operate by scaling up medical image information when displaying the medical image information. This scaling up of medical image information accounts for the fact that, in general, sizes of the sensors installed therein are relatively small. As a result, a projection DR, such as the above-mentioned CCD and CMOS DRs, may have defects that affect its image processing processes. These defects may result in relatively low quality images in terms of resolution, brightness, and contrast ratio, etc.
In detail, the FP DR displays superior x-ray images by using a photoelectric sensor. That is, the flat panel x-ray detecting (FPXD) device is one of the most advanced x-ray detecting device of all of the various DRs. FIG. 1 is a plan view showing a conventional flat panel x-ray detector 30. As shown in FIG. 1, the x-ray detector 30 may produce photographic images of objects having various vertical and horizontal sizes. The x-ray detector 30 includes an array substrate having a tile-like structure. Here, four array substrates 20 are combined with each other.
Referring to FIG. 1, the array substrates 20 of the x-ray detector 30 each include thin film transistor (TFT) arrays that are each arranged in rows and columns, read out circuits 26 that are connected to the TFT arrays, gate drivers 28, and analog-to-digital converters 27. Each TFT array includes cells 22, and each cell 22 includes a thin film transistor 23 and a p-i-n (PIN) photodiode 24. The PIN photodiode 24 includes a conductive layer and two electrodes that each respectively applies a voltage to both sides of the conductive layer. The conductive layer includes a p-type photoconductive layer into which p-type impurities are doped, a photoconductive layer into which impurities are not doped, and an n-type photoconductive layer into which n-type impurities are doped. A scintillator is formed on the PIN photodiode 24.
In conventional appliances, however, image quality of the image information obtained through the x-ray detector 30 may be decreased by various factors, such as a uniformity, or lack thereof, of lines 21a and 21b arranged on the array substrates 20, uniformity, or lack thereof, and defects of the photodiode 24, and leakage current levels, etc. Accordingly, in order to prevent a decrease in the image quality, an image correction operation is performed so as to adjust an offset voltage level of the gate and data lines 21a and 21b. 
Where the x-ray detector 30, including the array substrate of which four array substrates 20 are combined with each other (i.e., in a tile-like structure), is applied to take the photograph of the image, however, the offset correction may be imprecisely performed since the gate and data lines 21a and 21b may be separated from each other in accordance with the arrangements of the array substrates 20. Further, defects of the array substrates 20 may actually increase since external integrated circuits may be respectively bonded to every array substrate 20.